(Verb) Join up, become part of a group, generally a group that is going to go do something mischievous and/or unlawful. In an MMO, it means to become part of a
questing/
PvE party or PvP party.
Not that this is completely different from throwing in
the towel.
Dan: Bob and I are gonna go somke some weed and egg a house, you coming?
Frank: Sure, I'll thrown in for that shit any day.
Lamerrr:
LF2M BRD
Dissonance: BRD? I'll throw in, as long as you don't
ninja loot anything.